Tissue Structure and Function: combines two cores from the prior project period. Histology & Phenotyping and Retinal Anatomy & Physiology. It will be- co-directed by Paul FitzGerald and Andrew Ishida who were the directors of the former cores. This core will support anatomy and physiology research of ocular structures and retina with facilities utilized by multiple basic and clinical researchers. There is a strong need for these resources, especially to meet intermittent needs of laboratories that lack the equipment and expertise provided. At the same time, the two former cores are being consolidated to support other pressing needs of our investigators. 13 of our Core-eligible R012 investigators and two new faculty are anticipated to be moderate to extensive users in the next funding period.